/Engine/Source/Runtime/GeometryCore/Public/DynamicMeshEditor.h
Stitch together two loops of vertices with a quad-strip of triangles. Loops must be oriented (ordered) correctly for your use case. If loop edges are [a,b] and [c,d], then tris added are [b,a,d] and [a,c,d]
true if operation succeeded. If a failure occurs, any added triangles are removed via RemoveTriangles
bool StitchVertexLoopsMinimal ( const [TArray](API\Runtime\Core\Containers\TArray)< int > & VertexLoop1, const [TArray](API\Runtime\Core\Containers\TArray)< int > & VertexLoop2, [FDynamicMeshEditResult](API\Runtime\GeometryCore\FDynamicMeshEditResult) & ResultOut )